This invention relates to seals that comprise a body to which an end of a shackle, e.g., a solid or stranded steel cable, is attached, the free end being used to secure an article and the like. The free end is inserted into the seal for locking engagement with a locking collet in the seal, the free end for passing through the collet and seal and wedge locking to the collet and body in the withdrawal direction.
Of interest are commonly owned U.S. Pat. Nos. 5,582,447 (""447), 5,222,776 and 5,820,176, all relating to security seals and locks and which are incorporated, by reference herein in their entirety.
Each of the above patents generally disclose seals relating to the seal disclosed herein. In particular, the ""447 patent is of particular interest. This patent discloses a serpentine clip which forms a locking collet, made of steel or other materials which is located in a tapered bore of a housing. One end of a stranded cable is secured and locked to the housing by a first clip in a first tapered bore of the housing or may be swaged to the housing in the housing first bore. The seal has a second bore which is tapered and in which a second clip collet is located. When a cable or wire is inserted into the second tapered bore and through the second collet, the collet resiliently grips the cable or wire and displaces with it as the cable is withdrawn. The collet and tapered.bore permit any length of cable or wire to be inserted therethrough in the insertion direction which is toward the larger end of the tapered bore. The larger bore end permits the collet to expand and let the cable or wire slip therethrough.
Any attempt to withdraw the cable or wire pulls the collet therewith wedging the collet against the narrow end of the tapered bore, locking the collet to the cable or wire and to the housing. This housing is disclosed as comprising hardened metal or plastic, but in current practice preferably comprises die cast zinc.
However, thermoplastic material or zinc are not generally as strong as hardened steel and may not survive the rigors of use, especially tampering attempts in which the cable or wire is repetitively pulled back and forth to displace the collet therewith and defeat the seal. This action may cause the reciprocating clip collet to damage the seal housing internally and diminish the integrity of the seal. Also, evidence of such tampering attempts are not readily apparent from external observation of the locked seal.
The other patents noted above disclose similar security seals employing balls as the locking elements instead of the locking clip collet of the ""447 patent.
The present inventor recognizes a need for a seal such as disclosed in the ""447 patent discussed above, but which preferably uses other materials such as zinc. However, since these other materials are not as resistant to damage as steel, use of such materials may not be as desirable for this type of seal.
A seal according to the present invention comprises a housing made of a first material and having a first chamber with opposing first and second ends, the housing having an opening in communication with the ambient atmosphere and the chamber at least the chamber first end. A sleeve is in the chamber and has a tapered bore in communication with the opening and made of a second material different than the first material, the bore tapering in a first direction from a large transverse dimension adjacent to the chamber second end to a relatively smaller transverse dimension adjacent to the first chamber first end. A shackle has a free end for insertion into the sleeve tapered bore through the opening in an insertion direction opposite the first direction. A locking member with a bore is located in the first chamber, the locking member for receiving and for gripping the shackle passing through the locking member bore, the locking member being free to displace with the shackle in the first chamber and tapered bore and being arranged to wedge against the sleeve and shackle in the tapered sleeve bore when the shackle is displaced in the first direction.
In one aspect, the second material is stronger than the first material.
In a further aspect, the second material is harder than the first material.
In a further aspect, the sleeve is dimensioned to be fixed in place in the housing first chamber. Preferably the sleeve is made of steel. In a further aspect, the sleeve has a length dimension and has a slit along the length dimension so that the sleeve is radially resilient.
In a further aspect, the housing first chamber is tapered, the sleeve having an external surface that is complementary to the housing first chamber taper.
Preferably the locking member is serpentine.
In a further aspect, the sleeve bore defines an axis, the locking member comprising a plurality of interconnected U-shaped loop members extending along the axis.
In a further aspect, the housing is at least one of plastic and zinc, the locking member is steel, and the sleeve is steel.
In a further aspect, the sleeve has a length between said chamber ends smaller than the chamber length between the chamber ends, the chamber having a transverse dimension relative to the sleeve outer dimension so that the sleeve can displace in the chamber with the locking member and shackle wedged to each other in response to displacement of the secured shackle in a direction opposite the first direction.
In a further aspect, the sleeve has an outer peripheral surface, and wherein the sleeve tends to displace in the chamber in response to insertion of the shackle therein, further including means for securing the sleeve in the chamber in fixed position to restrain the displacement of the sleeve in response to said insertion. In a further aspect, the means for securing the sleeve includes staking means for staking the sleeve to the housing.
In a further aspect, a seal according to an embodiment of the present invention comprises a housing having first and second ends lying in spaced parallel planes, the housing having a first chamber terminating at the second end at a first opening in communication with the ambient atmosphere and a second chamber terminating at a third housing end at a second opening in communication with the ambient atmosphere, the second opening being medial the spaced parallel planes. A shackle having a third end is secured to the housing in the second chamber and has a free end exiting the second chamber through the second opening, the free end for insertion into the housing first chamber through the first opening in an insertion direction. A locking member with a bore is located in the first chamber, the locking member for receiving and for gripping the shackle passing through the locking member bore, the locking member and chamber being arranged to wedge the locking member in the chamber when the shackle is displaced in a withdrawal direction opposite the insertion direction.